SPIROLINITES. 



325 



foraminifera and infusoria, with spines of sponges, and a 

 considerable intermixture of polygonal spicula, resulting 

 from the decomposition of the large fibrous bivalve termed 

 Inoceramus, so common in the chalk. Intermingled with the 

 decidedly cretaceous forms, are minute fresh-water shells, 

 which have probably been derived from some modern de- 

 posit ; and many shields or cases of small marine crustaceans, 

 termed Cytherina ; which are related to the Cyprides.* 

 20. Spirolinites. — The chalk and flints often contain 



beautiful examples of a fora- 

 miniferous chambered shell, 

 of a crosier-like form, termed 

 Spirolinites ; of which several 

 species were discovered some 

 years since, by the Marquess 

 of Northampton. I subjoin 

 enlarged figures of two spe- 

 cies {Licjn. 60) ; and the fol- 

 lowing communication, with 

 which I have been honoured 

 by his Lordship. 



" I willingly comply with your 

 desire to communicate a short 

 note on the Sussex Spirolinites, 

 one species of which you have 

 been pleased to distinguish by 

 my name. I have found these 

 fossils in flint at Brighton, Kemp- 

 town, Kottingdean, Lewes, Hast- 

 ings, Steyning, Chichester, West 

 Stoke, and in the Isle of Wight ; 

 and one specimen in France. I 

 discovered about two hundred of these minute chambered 



Lign. 60.— Spirolinites in flint 



from the South Downs. 



Fig. 1. Spirolinites Lyellii. 



2. S. Murckisoni. 



have 



* The only notice of the Charing animalculites, is contained in Mr. 

 Williamson's memoir above referred to. It is to be hoped the intelli- 

 gent and liberal discoverer, Mr. Harris, will publish a full account of 

 the geological relations and organic contents of this curious deposit. 



